Patent · US Expired

Ringing voltage transfer circuit

US4201897A · kind A · utility

4Cited by
2References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 24, 1978
Grant dateMay 6, 1980
Priority date
Expiry dateNov 24, 1998

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M19/026
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A circuit which prepares a conductive path between a ringing voltage generator and a telephone subscriber loop circuit prior to the application of ringing voltage to the conductive path. Photo coupled switching and monitoring circuits are used to coordinate application of ringing voltage with operation of a ring relay which completes the circuit path between the ringing voltage generator and the loop circuit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.